This invention relates to a sheet finishing apparatus for selectively applying a finishing process such as jog discharge, alignment or binding to sheets fed from an image forming apparatus such as a laser printer or copier, and more particularly, relates to an image forming apparatus equipped with the sheet finishing apparatus.
A conventional sheet finishing apparatus is mounted to an image forming apparatus such as a laser printer or a copier, for example, as shown in FIG. 48. In such a sheet finishing apparatus, alignment rotating bodies, while rotating, touch a sheet fed to a finishing tray from the image forming apparatus to align the sheet at a predetermined aligning position established on one side of the finishing tray.
In such a conventional sheet finishing apparatus, when the sheets are discharged to the finishing tray with a center reference in which the center of the sheets with various sizes is aligned at a reference position, an edge of a smaller sheet is located far from the alignment rotating bodies, thereby making it difficult to align such a small sheet properly. When the sheet is discharged so that a side of the sheet is aligned at a side discharge reference position opposite to the center reference position in the finishing tray, it is still difficult to align the small sheet properly for the same reason. Furthermore, in the conventional sheet finishing apparatus described above, the finished sheets are stored in a storage tray arranged separately from a dedicated finishing tray after the sheets are finished and bound at the finishing tray that supports the discharged sheets. Therefore, an overall size of the finishing tray becomes larger. Moreover, the sheet needs to move a distance equivalent to at least the size of the sheet to be discharged from the finishing tray, thereby resulting in a larger apparatus and decreasing finishing efficiency.
An object of the present invention is to provide a sheet finishing apparatus that is compact and efficient, and that accurately aligns the sheets regardless of a position of the discharge reference or the size of the sheets that are discharged, and also to provide an image forming apparatus equipped with such a sheet finishing apparatus.